Characterization of the skin microbiome in normal and cutaneous squamous cell carcinoma affected cats and dogs.

Human cutaneous squamous cell carcinomas (SCCs) and actinic keratoses (AK) display microbial dysbiosis with an enrichment of staphylococcal species, which have been implicated in AK and SCC progression. SCCs are common in both felines and canines and are often diagnosed at late stages leading to high disease morbidity and mortality rates. Although recent studies support the involvement of the skin microbiome in AK and SCC progression in humans, there is no knowledge of this in companion animals. Here, we provide microbiome data for SCC in cats and dogs using culture-independent molecular profiling and show a significant decrease in microbial alpha diversity on SCC lesions compared to normal skin (P ≤ 0.05). Similar to human skin cancer, SCC samples had an elevated abundance of staphylococci relative to normal skin-50% (6/12) had >50% staphylococci, as did 16% (4/25) of perilesional samples. Analysis of Staphylococcus at the species level revealed an enrichment of the pathogenic species Staphylococcus felis in cat SCC samples, a higher prevalence of Staphylococcus pseudintermedius in dogs, and a higher abundance of Staphylococcus aureus compared to normal skin in both companion animals. Additionally, a comparison of previously published human SCC and perilesional samples against the present pet samples revealed that Staphylococcus was the most prevalent genera across human and companion animals for both sample types. Similarities between the microbial profile of human and cat/dog SCC lesions should facilitate future skin cancer research. IMPORTANCE: The progression of precancerous actinic keratosis lesions (AK) to cutaneous squamous cell carcinoma (SCC) is poorly understood in humans and companion animals, despite causing a significant burden of disease. Recent studies have revealed that the microbiota may play a significant role in disease progression. Staphylococcus aureus has been found in high abundance on AK and SCC lesions, where it secretes DNA-damaging toxins, which could potentiate tumorigenesis. Currently, a suitable animal model to investigate this relationship is lacking. Thus, we examined the microbiome of cutaneous SCC in pets, revealing similarities to humans, with increased staphylococci and reduced commensals on SCC lesions and peri-lesional skin compared to normal skin. Two genera that were in abundance in SCC samples have also been found in human oral SCC lesions. These findings suggest the potential suitability of pets as a model for studying microbiome-related skin cancer progression.

Dual pathogenicity island transfer by piggybacking lateral transduction.

Lateral transduction (LT) is the process by which temperate phages mobilize large sections of bacterial genomes. Despite its importance, LT has only been observed during prophage induction. Here, we report that superantigen-carrying staphylococcal pathogenicity islands (SaPIs) employ a related but more versatile and complex mechanism of gene transfer to drive chromosomal hypermobility while self-transferring with additional virulence genes from the host. We found that after phage infection or prophage induction, activated SaPIs form concatamers in the bacterial chromosome by switching between parallel genomic tracks in replication bubbles. This dynamic life cycle enables SaPIbov1 to piggyback its LT of staphylococcal pathogenicity island vSaα, which encodes an array of genes involved in host-pathogen interactions, allowing both islands to be mobilized intact and transferred in a single infective particle. Our findings highlight previously unknown roles of pathogenicity islands in bacterial virulence and show that their evolutionary impact extends beyond the genes they carry.

Epidemiological Profile of Patients with Infective Endocarditis at three Tertiary Centers in Brazil from 2003 to 2017

Abstract Background Infective endocarditis (IE) is a disease with high morbimortality and an increasing incidence. With improved diagnosis and treatment, a number of epidemiological changes have been reported over time. Objectives We sought to describe the epidemiological profile, mortality predictors, and analysis of a possible microbiological transition in patients admitted to three tertiary centers in Brazil. Methods In this cross-sectional retrospective study, data from 211 patients with definite or probable IE were analyzed according to the modified Duke criteria between 2003 and 2017. The association between categorical variables was assessed using the chi-square or Fisher's exact test, and binary logistic models were built to investigate mortality. We considered p <0.05 statistically significant. Results The median age of the sample was 48 (33-59) years old, 70.6% were men, and the most prevalent pathogen was Staphylococcus spp. (19%). Mortality was 22.3%, with increasing age being the leading risk factor for death (p = 0.028). Regarding the location of the disease, native valves were the most affected site, with the aortic valve being more affected in men than women (p = 0.017). The mean number of cases of Staphylococcus spp. (τ = 0.293, p = 0.148) and Streptococcus spp. (τ = -0.078, p = 0.727) has remained stable over the years. Conclusion No trend towards reduced or increased mortality was evident between 2003 and 2017. Although Staphylococcus spp. were the most prevalent pathogen, the expected epidemiological transition could not be observed.

Investigating Pathogenicity and Virulence of Staphylococcus pettenkoferi: An Emerging Pathogen.

Staphylococcus pettenkoferi is a coagulase-negative Staphylococcus identified in 2002 that has been implicated in human diseases as an opportunistic pathogenic bacterium. Its multiresistant character is becoming a major health problem, yet the pathogenicity of S. pettenkoferi is poorly characterized. In this study, the pathogenicity of a S. pettenkoferi clinical isolate from diabetic foot osteomyelitis was compared with a Staphylococcus aureus strain in various in vitro and in vivo experiments. Growth kinetics were compared against S. aureus, and bacteria survival was assessed in the RAW 264.7 murine macrophage cell line, the THP-1 human leukemia monocytic cell line, and the HaCaT human keratinocyte cell line. Ex vivo analysis was performed in whole blood survival assays and in vivo assays via the infection model of zebrafish embryos. Moreover, whole-genome analysis was performed. Our results show that S. pettenkoferi was able to survive in human blood, human keratinocytes, murine macrophages, and human macrophages. S. pettenkoferi demonstrated its virulence by causing substantial embryo mortality in the zebrafish model. Genomic analysis revealed virulence factors such as biofilm-encoding genes (e.g., icaABCD; rsbUVW) and regulator-encoding genes (e.g., agr, mgrA, sarA, saeS) well characterized in S. aureus. This study thus advances the knowledge of this under-investigated pathogen and validates the zebrafish infection model for this bacterium.

Simple indictor of increased blood culture contamination rate by detection of coagulase-negative staphylococci.

Coagulase-negative staphylococci (CoNS) are the most frequent contaminating bacteria; therefore, we aimed to investigate an indicator of CoNS to predict the increase in blood culture contamination rate (ConR). We performed a retrospective study of selected patients, who underwent blood culture testing. Contamination was defined as the presence of either one of two or more sets of skin-resident bacteria, except for cases with a low likelihood of contamination based on clinical aspects. We calculated the monthly ConR [(total number of contaminated cases per month)/(total number of blood culture sets collected per month) × 100] and analysed the ConR prediction ability using the following four indicators: the number of CoNS-positive sets of blood cultures, cases with at least one CoNS-positive blood culture set, cases with only one CoNS-positive blood culture set, and cases of contamination by CoNS. Cases with CoNS-positive blood cultures correlated with ConR (r = 0.85). Although the area under the receiver operating characteristic curve for the number of cases with ConR ≥ 2.5 differed significantly from that of the number of cases contaminated by CoNS, the negative predictive value was high, reaching up to 95.5% (95% confidential interval 87.3-99.1). The number of CoNS-positive cases could help predict an increase in ConR ≥ 2.5.

One Affectionate Puppy: A Case of Septic Arthritis Due to Staphylococcus Pseudintermedius.

We describe a case of septic arthritis caused by Staphylococcus pseudintermedius, a common colonizer of dogs that has emerged as a rare human pathogen. Our patient presented with ankle pain and swelling and was treated adequately with cefazolin/cephalexin and arthrotomy. S. pseudintermedius is often misidentified as other coagulase-positive staphylococcal species and has high rates of methicillin and nonpenicillin antibiotic resistance.

Visual outcome of endogenous endophthalmitis in Thailand.

To evaluate a 10-year visual outcome of endogenous endophthalmitis (EE) patients. A 10-year retrospective chart review of EE patients. Thirty-eight patients (40 eyes) were diagnosed with EE at the mean age of 42. Among the identifiable pathogens (71.1% culture positive), the causative agents were predominantly gram-negative bacteria (48.1%). The most common specie was Klebsiella pneumoniae (25.9%). About a quarter of the patients required surgical eye removal, and the remaining 45.7% had visual acuity (VA) worse than hand motion at one month after the infectious episode. The most common complication was ocular hypertension (52.5%). Poor initial VA was significantly associated with a worse visual outcome in the early post-treatment period (p 0.12, adjusted OR 10.20, 95% CI 1.65-62.96). Five patients continued to visit the clinic for at least ten years. One patient had gained his vision from hand motion to 6/7.5. Two patients had visual deterioration, one from corneal decompensation, and the other from chronic retinal re-detachment. Two patients developed phthisis bulbi, with either some VA perception of light or no light perception. Poor initial VA is the only prognostic factor of a poor early post-treatment visual outcome of EE.

Abnormal composition of microbiota in the gut and skin of imiquimod-treated mice.

Psoriasis is a chronic, inflammatory skin disease. Although the precise etiology of psoriasis remains unclear, gut-microbiota axis might play a role in the pathogenesis of the disease. Here we investigated whether the composition of microbiota in the intestine and skin is altered in the imiquimod (IMQ)-treated mouse model of psoriasis. Topical application of IMQ to back skin caused significant changes in the composition of microbiota in the intestine and skin of IMQ-treated mice compared to control mice. The LEfSe algorithm identified the species Staphylococcus lentus as potential skin microbial marker for IMQ group. Furthermore, there were correlations for several microbes between the intestine and skin, suggesting a role of skin-gut-microbiota in IMQ-treated mice. Levels of succinic acid and lactic acid in feces from IMQ-treated mice were significantly higher than control mice. Moreover, the predictive functional analysis of the microbiota in the intestine and skin showed that IMQ caused alterations in several KEGG pathways. In conclusion, the current data indicated that topical application with IMQ to skin alters the composition of the microbiota in the gut and skin of host. It is likely that skin-gut microbiota axis plays a role in pathogenesis of psoriasis.

Coagulase negative Staphylococcus bacteremia in hematopoietic stem cell transplant recipients: Clinical features and molecular characterization.

The purpose of our study was to investigate the epidemiology of coagulase negative staphylococci (CoNS) responsible for bacteremia in hematopoietic stem cell transplant (HSCT) recipients and to determine the prevalence and the genetic background of methicillin resistance. The prevalence of CoNS bacteremia was 7.4% (54/728), higher in allograft (10.7%) than in autograft (4.7%) recipients. A sepsis or a septic shock were observed in 9% of cases. No deaths were attributable to CoNS bacteremia. The methicillin resistance rate was 81%. All MR-CoNS, harbored mecA gene and 90% were typeable with SCCmec typing using PCR amplification. The SCCmec type IV was the most frequent (44%). Clonal dissemination of MR- Staphylococcus epidermidis strains was limited. Our study showed a low prevalence and favorable outcome of CoNS bacteremia in HSCT recipients with limited clonal diffusion. However, they were associated with a significant rate of severe infections and a high rate of methicillin resistance, mediated by SCCmec IV element in most cases.

Epidemiology and Pathogenesis of Staphylococcus Bloodstream Infections in Humans: a Review.

Staphylococci are among the most frequent human microbiota components associated with the high level of bloodstream infection (BSI) episodes. In predisposed patients, there is a high risk of transformation of BSI episodes to sepsis. Both bacterial and host factors are crucial for the outcomes of BSI and sepsis. The highest rates of BSI episodes were reported in Africa, where these infections were up to twice as high as the European rates. However, there remains a great need to analyze African data for comprehensive quantification of staphylococcal BSI prevalence. The lowest rates of BSI exist in Australia. Asian, European, and North American data showed similar frequency values. Worldwide analysis indicated that both Staphylococcus aureus and coagulase-negative staphylococci (CoNS) are the most frequent BSI agents. In the second group, the most prevalent species was Staphylococcus epidermidis, although CoNS were not identified at the species level in many studies. The lack of a significant worldwide decrease in BSI episodes indicates a great need to implement standardized diagnostic methods and research etiological factors using advanced genetic methods.

Causative bacteria associated with a clinically relevant postoperative pancreatic fistula infection after distal pancreatectomy.

PURPOSE: Clinically relevant postoperative pancreatic fistulas (CR-POPF) occurring after distal pancreatectomy often cause intra-abdominal infections. We monitored the presence of bacterial contamination in the ascitic fluid after distal pancreatectomy to clarify the bacterial origin of intra-abdominal infections associated with CR-POPF. METHODS: In 176 patients who underwent distal pancreatectomy, ascitic fluid bacterial cultures were performed on postoperative days (POD) 1-4 and when the drainage fluid became turbid. The association between postoperative ascitic bacterial contamination and CR-POPF incidence was investigated. RESULTS: CR-POPF occurred in 18 cases (10.2%). Among the patients with CR-POPF, bacterial contamination was detected in 0% on POD 1, in 38.9% on POD 4, and in 72.2% on the day (median, day 9.5) when the drainage fluid became turbid. A univariate analysis revealed a significant difference in ascitic bacterial contamination on POD 4 (p < 0.001) and amylase level on POD 3-4 (p < 0.001). A multivariate analysis revealed the amylase level and ascitic bacterial contamination on POD 4 to be independent risk factors. CONCLUSIONS: In the CR-POPF group, ascitic bacterial contamination was not observed in the early postoperative stage, but the bacterial contamination rate increased after pancreatic juice leakage occurred. Therefore, CR-POPF-related infections in distal pancreatectomy may be caused by a retrograde infection of pancreatic juice.

Vancomycin-resistant enterococci and coagulase-negative staphylococci prevalence among patients attending at Felege Hiwot Comprehensive Specialized Hospital, Bahir Dar, Ethiopia.

BACKGROUND: Vancomycin resistant enterococci (VRE) and vancomycin resistance coagulase negative staphylococci (VRCoNS) are common pathogens causing difficult to treat health care associated infections (HAI). Hence, the World Health Organization listed VRE as one of the high priority pathogens for new antibiotic discovery and antimicrobial resistance surveillance. Despite this, data on the prevalence of VRE and VRCoNS in Ethiopia is scarce. Thus, the present study determined prevalence of VRE and VRCoNS among patients attending Felege-Hiwot comprehensive specialized hospital, Ethiopia. METHODS: A hospital based cross-sectional study was conducted on 384 patients selected conveniently from February to March 2020. Data on demographic and clinical variables were collected using a structured questionnaire by face-to-face interview. Simultaneously urine, venous blood and wound swab were collected and processed following standard bacteriological technique. Antimicrobial susceptibility test was performed by minimum inhibitory concentration method using E-test for vancomycin and Kirby-Bauer disc diffusion method for other classes of antibiotics. Data was entered and analyzed using SPSS version 23. Logistic regression was performed to identify factors associated with VRE infection. P. value < 0.05 was considered as statistically significant. RESULTS: The prevalence of enterococci and CoNS were 6.8% and 12% respectively. The prevalence of VRE was 34.61% (9/26), while all CoNS (46 isolates) were susceptible to vancomycin. The majority (66.7%) of VRE was isolated from blood samples. Furthermore all VRE (100%), 58.8% of vancomycin susceptible enterococci and 45.7% of CoNS were multidrug resistant (MDR). Having educational level of secondary school and below (AOR = 12.80, CI = 1.149-142.5), previous exposure to catheterization (AOR = 56.0, CI = 4.331-724.0) and previous antibiotic use practice (AOR = 26.25, CI = 3.041-226.2) were a significant associated explanatory factor for VRE infection. CONCLUSIONS: The prevalence of vancomycin resistance enterococci, which is also multidrug resistant, was significantly high. Though no vancomycin resistance CoNS detected, the MDR level of CoNS was high. Thus to limit enterococci and CoNS infections and MDR development, focused infection prevention measures should be implemented.

Genomic investigation of clinically significant coagulase-negative staphylococci.

Introduction. Coagulase-negative staphylococci have been recognized both as emerging pathogens and contaminants of clinical samples. High-resolution genomic investigation may provide insights into their clinical significance.Aims. To review the literature regarding coagulase-negative staphylococcal infection and the utility of genomic methods to aid diagnosis and management, and to identify promising areas for future research.Methodology. We searched Google Scholar with the terms (Staphylococcus) AND (sequencing OR (infection)). We prioritized papers that addressed coagulase-negative staphylococci, genomic analysis, or infection.Results. A number of studies have investigated specimen-related, phenotypic and genetic factors associated with colonization, infection and virulence, but diagnosis remains problematic.Conclusion. Genomic investigation provides insights into the genetic diversity and natural history of colonization and infection. Such information allows the development of new methodologies to identify and compare relatedness and predict antimicrobial resistance. Future clinical studies that employ suitable sampling frames coupled with the application of high-resolution whole-genome sequencing may aid the development of more discriminatory diagnostic approaches to coagulase-staphylococcal infection.

Phenotypic and genotypic virulence features of staphylococcal strains isolated from difficult-to-treat skin and soft tissue infections.

Chronic infections represent an important burden on the healthcare system and have a significant impact on the patients' quality of life. While Staphylococcus spp. are commensal bacteria, they can become pathogenic, leading to various types of infections. In this study we aimed to characterize the virulence profiles of staphylococcal strains involved in difficult-to-treat skin and soft tissue infections, from both phenotypic and genotypic points of view. Phenotypic ability of the strains to secrete soluble virulence factors was assessed by a culturing dependent assay and their capacity to develop biofilms on inert substrate was screened by an adapted crystal violet microtiter method. We also tested the presence of several virulence genes by PCR. Most of the studied strains were isolated from purulent secretions of acne lesions and frequently secreted two or three soluble virulence factors. Most frequently secreted soluble virulence factors were caseinase (89%), lipase (71%) and lecithinase (67%). Almost half of the strains produced a well-represented biofilm. The molecular characterization showed the presence of the genes cna, hlg, clfA, and clfB. Staphylococcal strains that produce difficult-to-treat skin and soft tissue infections seem to be characterized by an enhanced ability to produce different soluble virulence factors and to develop biofilms in vitro. Further studies need to be developed in other Staphylococcus spp. infections in order to confirm this hypothesis.

An in vitro study on Staphylococcus schweitzeri virulence.

Staphylococcus schweitzeri belongs to the Staphylococcus aureus-related complex and is mainly found in African wildlife; no infections in humans are reported yet. Hence, its medical importance is controversial. The aim of this work was to assess the virulence of S. schweitzeri in vitro. The capacity of African S. schweitzeri (n = 58) for invasion, intra- and extracellular cytotoxicity, phagolysosomal escape, coagulase activity, biofilm formation and host cell activation was compared with S. aureus representing the most common clonal complexes in Africa (CC15, CC121, CC152). Whole genome sequencing revealed that the S. schweitzeri isolates belonged to five geographical clusters. Isolates from humans were found in two different clades. S. schweitzeri and S. aureus showed a similar host cell invasion (0.9 vs. 1.2 CFU/Vero cell), host cell activation (i.e. expression of pro-inflammatory cytokines, 4.1 vs. 1.7 normalized fold change in gene expression of CCL5; 7.3 vs. 9.9 normalized fold change in gene expression of IL8, A549 cells) and intracellular cytotoxicity (31.5% vs. 25% cell death, A549 cells). The extracellular cytotoxicity (52.9% vs. 28.8% cell death, A549 cells) was higher for S. schweitzeri than for S. aureus. Nearly all tested S. schweitzeri (n = 18/20) were able to escape from phagolysosomes. In conclusion, some S. schweitzeri isolates display virulence phenotypes comparable to African S. aureus. S. schweitzeri might become an emerging zoonotic pathogen within the genus Staphylococcus.

Comparison of microbiological quality between illegal and inspected salami

The consumption of meat and meat products can pose consumers into risk due to the presence of biological hazards that can cause foodborne diseases. Thus, this study aimed to compare the microbiological quality of illegal and inspected salami sold in the state of São Paulo, Brazil. For this purpose, 80 salami samples (40 illegal and 40 inspected) were purchased and their microbiological quality was assessed according to the protocol established by the Brazilian Ministry of Health. All samples were considered as acceptable for consumption according to the Brazilian law. However, the samples of illegal salami were significantly higher contaminated with bacteria belonging to the genus Staphylococcus (p = 0.002) and had a higher trend to be contaminated with total coliforms (p = 0.08) and thermotolerant ones (p = 0.07) compared to inspected salami. Salmonella spp. and coagulase-positive Staphylococcus were not detected. In conclusion, although all samples were considered as safe for consumption, illegal salami had a worse microbiological quality when compared to inspected ones.

Multidrug resistance bacteremia in neonates and its association with late-onset sepsis and Coagulase-negative Staphylococci.

INTRODUCTION: This study aimed to assess the association between multidrug resistance (MDR) and late-onset sepsis (LOS) among newborns with bloodstream infection (BSI). METHODOLOGY: In this cross-sectional study, we routinely tested every newborn with a presumptive diagnosis of sepsis admitted to the largest reference maternity hospital in Lima, Peru for BSI over an 18-month period. We tested every isolate for MDR by using the disk-diffusion method and assessed its associated factors by using a robust Poisson regression analysis with a particular focus on its association with LOS (vs. early-onset sepsis, EOS). RESULTS: We analyzed a total of 489 subjects, including 340 (69%) newborns with LOS, and estimated an MDR rate of 80% (95% confidence interval, CI: 76%-83%), which was significantly higher (p-value < 0.001) among LOS (85%; 95% CI: 81%-89%) than EOS cases (67%; 95% CI: 59%-75%). The primary isolate was coagulase-negative Staphylococci (CoNS) (60%), which exhibited a limited subset of antibiotic MDR patterns, most of which were characterized by their resistance to cefoxitin, gentamicin, and clindamycin and levofloxacin. Overall, the prevalence of MDR was higher among LOS compared to EOS cases (adjusted prevalence ratio [aPR] = 1.28; 95% CI: 1.14-1.45), and among BSI due to CoNS compared to other bacteria (Apr = 1.10; 95% CI: 1.01-1.20). CONCLUSIONS: MDR among newborns with sepsis is exceptionally high, being even higher among those with LOS than newborns with EOS, and among those infected with CoNS compared to other bacteria. Furthermore, CoNS exhibited a limited subset of MDR patterns, which could be used to guide therapeutic decisions.

Papel del Staphylococcus caprae en la infección nosocomial / Role of Staphylococcus caprae in nosocomial infection

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Differentiating Staphylococcus infection-associated glomerulonephritis and primary IgA nephropathy: a mass spectrometry-based exploratory study.

Staphylococcus infection-associated glomerulonephritis (SAGN) and primary IgA nephropathy (IgAN) are separate disease entities requiring different treatment approaches. However, overlapping histologic features may cause a diagnostic dilemma. An exploratory proteomic study to identify potential distinguishing biomarkers was performed on formalin fixed paraffin embedded kidney biopsy tissue, using mass spectrometry (HPLC-MS/MS) (n = 27) and immunohistochemistry (IHC) (n = 64), on four main diagnostic groups-SAGN, primary IgAN, acute tubular necrosis (ATN) and normal kidney (baseline transplant biopsies). Spectral counts modeled as a negative binomial distribution were used for statistical comparisons and in silico pathway analysis. Analysis of variance techniques were used to compare groups and the ROC curve to evaluate classification algorithms. The glomerular proteomes of SAGN and IgAN showed remarkable similarities, except for significantly higher levels of monocyte/macrophage proteins in SAGN-mainly lysozyme and S100A9. This finding was confirmed by IHC. In contrast, the tubulointerstitial proteomes were markedly different in IgAN and SAGN, with a lower abundance of metabolic pathway proteins and a higher abundance of extracellular matrix proteins in SAGN. The stress protein transglutaminase-2 (TGM2) was also significantly higher in SAGN. IHC of differentially-expressed glomerular and tubulointerstitial proteins can be used to help discriminate between SAGN and IgAN in ambiguous cases.